/**
 * Copyright 2010 Longyi Qi
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

#import <Foundation/Foundation.h>

@interface NGDocAttributesUpdate : NSObject {
	NSMutableArray *_attributesUpdateArray;
}

- (NGDocAttributesUpdate *) addAttributeWithKey:(NSString *)key andOnlyNewValue:(NSString *)value;
- (NGDocAttributesUpdate *) addAttributeWithKey:(NSString *)key oldValue:(NSString *)oldValue andNewValue:(NSString *)newValue;

- (NSArray *) keys;
- (BOOL) hasOldValue:(NSString *)key;
- (NSString *) oldValueForKey:(NSString *)key;
- (NSString *) newValueForKey:(NSString *)key;

+ (NGDocAttributesUpdate *) emptyAttributesUpdate;

@end
